Simply supported deep beam deflection

I have a problem with simply supported deep beam which has a uniformly distributed load. The beam is simply supported at both ends but I have to consider the results for the following 3 scenarios
- where the support is at the bottom of each end of the beam
- where the support is at the mid point at each end of the beam
- where support is at top of each end of the beam

I have run this using FEA and I'm finding significantly different deflections and stresses when the beam is supported at the midpoint at its end and the other two scenarios...can anyone explain the exact reasoning for this?

The deep beam does not follow the Euler-Bernoulli beam equation assumptions (particularly, that of plane sections remain plane). It is more like a plate problem, and different boundary conditions on a plate give different solutions.

Thanks for your reply. I'm aware of that but could you be more specific on the difference that would occur where you have a pinned support at the bottom of a beams end and a pinned support at the mid-height of a beams end?